Washington: Mexican President Felipe Calderon took his opposition to a new immigration law in border state Arizona to US Congress on Thursday, saying it "ignores a reality that cannot be erased by decree”.

The Mexican leader also told lawmakers reluctant to take up the immigration issue this year that comprehensive immigration reform is crucial to securing the two countries` common border.

Calderon, the first foreign national leader to address US Congress this year, said he strongly disagrees with the Arizona law that requires police to question people about their immigration status if there is reason to suspect they are in the US illegally.

"It is a law that not only ignores a reality that cannot be erased by decree but also introduced a terrible idea using racial profiling," he said to cheers, mainly from the Democratic side of the chamber.

Speaking in English, he warned of the risk when "core values we all care about are breached”.

Arizona`s senior Republican senator, John McCain was not present at the joint meeting, while the office of Jon Kyl, the other Arizona senator, did not respond immediately to inquiries about whether Kyl was present. McCain attended a lunch with Calderon at the State Department on Wednesday.

And broaching another highly sensitive issue, he urged Congress to restore a ban on assault weapons, saying easy access to high-powered weapons is contributing to drug-related violence along the border.

Calderon also took up the Arizona law in a meeting on Wednesday with President Barack Obama, who referred to the law as a "misdirected expression of frustration”.

The Mexican leader said his country was doing its best, by promoting more jobs and opportunities at home, to reduce the flow of immigrants to the United States.